Getting your foot in the door??

I have just recently moved to Chicago and am really interested and eager to work for a trading firm in Chicago. I have graduated college and was working as a financial representative for Northwestern Mutual and have had a couple of investment internships while I was in college. My academic background is not spectacular but not that bad either. I have been researching jobs online and lack the experience in the industry.

What would you suggest in terms of getting a career started? I am willing to work long hours and start from the bottom. (over night shifts, etc.) Any suggestions would be really appreciated, thanks.